Addiction to alcohol and other drugs continues to be a major problem with serious societal and health-related consequences. Current basic research on the etiology of alcoholism is based on the premise that this complex behavior pattern is jointly determined by organismic (including genetic), environmental and experiential variables. The research proposed here is especially concerned with the roles played by environment and experience in the modulation of physiological effects that may be critically involved in regulating alcohol intake and in determining the reinforcing value of alcohol. Recent studies have indicated that ambient environmental temperature may affect alcohol consumption in laboratory animals. This effect appears to be due to the inverse relationship between ambient temperature and the hypothermic response to alcohol. Our specific hypothesis is that alcohol intake is regualted by the magnitude of its thermal effect. When there is a large drop in body temperature following ingestion of alcohol, subsequent consumption is reduced, apparently as a result of taste aversion condition. However, if alcohol-induced hypothermia is blocked by exposure to a warm ambient temperateure, the aversive consequences of alcohol appear to be reduced. The experiments proposed here will systematically examine the effects of ambient temperature and alcohol dose on three types of alcohol-reinforced behavior: oral self administration, conditioned taste aversion and conditioned place preference/aversion. They will addres several alternative exdplanations of the effect of ambient temperature, including possible changes in motivation, pharmacokinetics or other physiological/biochemical effects of alcohol. This research may eventually identify an important link between alcohol's affective properties and a specific physiological effect of alcohol. This link would justify increased study of alcohol's hypothermic effect and its possible role in the development of excessive drinking and alcoholism. The long-term goal of this research is to increase our understanding of the biobehavioral processes involved in the regulation of alcohol intake in order to improve our understanding of alcoholism. Such efforts should help us to recognize increased risk of alcohol abuse, to devise more efficient and effective treatments for alcoholism and to outline more effective prevention strategies.